The suspected Texas serial bomber has been killed during a confrontation with police, according to US media reports.

Two law enforcement officials told NBC News that the suspect detonated a device as he was being pursued by police.

Police had earlier reported an officer involved shooting on the North Interstate 35 but it was unclear whether it was related to the spate of bombings.

Two people have been killed and four others injured in four different explosions in Austin over the last 17 days.

A fifth explosion at a FedEx distribution centre placed the state on high alert.

A 39-year old man and a 17-year-old boy was killed and two women were injured in two separate parcel bomb blasts on March 12.

And on Sunday, two men aged 22 and 23 were injured in an explosion triggered by a tripwire.

Authorities had warned that the devices appeared to be getting more sophisticated.

"We are clearly dealing with a serial bomber," Austin Police Chief Brian Manley said. "We will have to determine if we see a specific ideology behind this."